Add type tooltip to function in result

src/lib/MyLib.hs

@@ -15,7 +15,7 @@ module MyLib
   , runPrintQueryAll
   , spTreeToPaths
   , renderComposedFunctions, renderComposedFunctionsStr, parseComposedFunctions
-  , renderFunction, parseFunction
+  , renderFunction, parseFunction, renderTypedFunction
   , Function(..), TypedFunction, UntypedFunction
   , FullyQualifiedType(..), textToFullyQualifiedType, fullyQualifiedTypeToText
   , Graph
@@ -251,6 +251,18 @@ renderFunction :: Function typeSig -> BS.ByteString
 renderFunction fn =
   _function_package fn <> ":" <> _function_module fn <> "." <> _function_name fn
 
+-- | Render a function's name (output of 'renderFunction') and its FROM and TO type.
+renderTypedFunction
+  :: TypedFunction
+  -> (BS.ByteString, (FullyQualifiedType, FullyQualifiedType))
+  -- ^ (output of 'renderFunction', (FROM type, TO type))
+renderTypedFunction fn =
+  ( renderFunction fn
+  , (Json.functionType_arg sig, Json.functionType_ret sig)
+  )
+  where
+    sig = _function_typeSig fn
+
 -- | Parse e.g. "text-2.0.2:Data.Text.Encoding.encodeUtf16BE" to an untyped 'Function'
 parseFunction :: BS.ByteString -> Maybe UntypedFunction
 parseFunction bs =

src/server/Server/Pages/Search.hs

@@ -13,14 +13,37 @@ import qualified Data.Text as T
 import Servant.Server (Handler)
 import qualified Server.Monad as MyLib
 import qualified MyLib
+import Data.List (intersperse)
 
 page :: MyLib.Graph -> T.Text -> T.Text -> Handler (Html ())
 page graph src dst = pure $ do
   p_ $ "Hi there, you entered src=" <> mono (toHtml src) <> ", dst=" <> mono (toHtml dst)
-  forM_ (map MyLib.renderComposedFunctions results) $ \result -> do
-    mono (toHtml result)
-    br_ []
+  forM_ results $ \result -> renderResult result >> br_ []
   where
-    mono = span_ [style_ "font-family: monospace, monospace; background-color: rgb(200, 200, 200);"]
     maxCount = 20
-    results = take maxCount $ MyLib.runQueryAll maxCount (MyLib.textToFullyQualifiedType src, MyLib.textToFullyQualifiedType dst) graph
+
+    results =
+      take maxCount $ MyLib.runQueryAll
+        maxCount
+        (MyLib.textToFullyQualifiedType src, MyLib.textToFullyQualifiedType dst)
+        graph
+
+    renderResult :: [MyLib.TypedFunction] -> Html ()
+    renderResult fns =
+      let nameWithTypeLst = map MyLib.renderTypedFunction (reverse fns)
+          renderSingleFn (name, (fromTy, toTy)) =
+            let typeSig = T.unwords $
+                  [ "::"
+                  , MyLib.fullyQualifiedTypeToText fromTy
+                  , "->"
+                  , MyLib.fullyQualifiedTypeToText toTy
+                  ]
+            in mono (toHtml name) `with` [title_ typeSig]
+      in mconcat $ intersperse (mono " . ") $ map renderSingleFn nameWithTypeLst
+
+    mono =
+      let style = style_ $ T.intercalate "; " $
+            [ "font-family: monospace, monospace"
+            , "background-color: rgb(200, 200, 200)"
+            ]
+      in span_ [style]